Loose leaf binder



June 7, 1938.

LOOSE LEAF BINDER Filed Dec. 25, 1936 A. e. LOTTER 2,119,63

Patented June 7, 1938 UNITED STATES LOOSE LEAF BINDER Adolph'G. Lotter, Milwaukee, Wis., Stationers Loose Leaf Company,

assignor to Milwaukee,

Wis., a, corporation of Wisconsin Application December 4 Claims.

This invention relates to loose leaf binders and refers particularly to the so-called ring binders. As is well-known, binders of this type comprise a plurality of complementary impaling prongs arranged for endwise engagement to form closed loops to retain the sheets or leaves in the binder.

Inasmuch as these impaling prongs are mounted at their extreme inner ends upon relatively movable members, difiiculty has always been experienced in maintaining proper alignment between their outer free ends.

In the event of misalignment between the prongs the resulting offsets of their free ends tear the sheets as they are slid across the rings and in general result in a very unsatisfactory condition.

To obviate this difficulty attempts have been made in the past to provide an interlocking connection between the free ends of the prongs, but the expedients heretofore employed either did not secure the prongs against all relative lateral motion, or they did not have a sufficiently wide mutual guiding action upon each other. 7

25 This latter objection was particularly noticeable in ring binders wherein the free end of one impaling prong carried a projecting pin for entry into an aperture in the free end of the other impaling prong.

30 With these and other objections to past and existing ring binder constructions in mind, it

is an object of the present invention to provide an improved interlocking connection for the impaling prongs of a ring binder.

More specifically it is an object of this invention to provide a connection for the complementary impaling prongs of loose leaf ring binders, which is so designed that it will securely hold the prongs against all relative lateral motion, and also mutually guide the prongs into proper relative positions from a comparatively wide misalignment.

With the above and other objects in view which 45 will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the 23, 1936, Serial No. 117,368

best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a perspective view illustrating part of a ring binder and showing the application of this invention thereto;

Figure 2 is an enlarged side View of the free end portions of two complementary prongs, spaced apart and in position for endwise engagement; and

Figure 3 is a top view of the impaling prongs illustrated in Figure 2.

Referring now particularly ing drawing, in which like numerals indicate like parts throughout the several views, the numeral 5 designates the back of a conventional ring type binder to which covers 6 are secured in the customary manner.

The back 5 encloses mechanism (not shown) for mounting the complementary impaling prongs I and 8 at their inner ends.

This mounting mechanism, as is well known, holds the complementary impaling prongs 'l and 8 with a spring tension either in the closed position illustrated in Figure 1 with their free ends engaged, or in an open position with their free ends spaced apart.

When the binder rings are closed, it is essential that the connection between the prongs be free from projections or oifsets and that one prong forms substantially an uninterrupted continuation of the other so as to permit free sliding of the leaves from one prong onto the other.

To this end, a novel interlocking connection 9 is provided. This connection may be briefly described as two engaging bifurcations l0 and H formed respectively on the free ends of the impaling prongs 1 and B.

The two bifurcated ends of the prongs are substantially identical and in each instance the bifurcation is formed by two V-shaped notches l2 out into opposite sides of the free end portion of the impaling prong. On the prong 8 the notches l2 are at opposite sides of the median plane of the ring and on the other prong they lie one above the other on the median plane of the ring. In each instance the notches I2 are cut so that their bottoms 53 form an acute angle with the axis of the prong and meet at a point I4 coinciding with the axis of the prong inwardly of the outer end thereof. As a consequence, the inner walls of the bifurcations comprise four substantially triangular plane faces [5.

Inasmuch as the bifurcations on the free ends of the two impaling prongs are substantially of the free end portions disposed in the positions to the accompany- V and in the event of misalignment between the 'free ends of the prongs, within normal limits,

the mutual guiding effect of the faces l guides the ends of the prongs into proper alignment, the spring tension urging .the prongs closed being sufiicient for this purpose.

From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the pertinent art, that this invention greatly improves the ring type loose leaf binder by eliminating one of its most common and universal objections.

What I claim as my invention is;

1. In a loose leaf binder: two impaling prongs; means for mounting the impaling prongs at one end in such a manner that their free ends are endwise engageable to form a closed loop; an interlocking connection between the free ends of the. impaling prongs comprising, a bifurcation on the free end of each prong, said bifurcations being arranged at right angles to each other so that upon interengagementof the bifurcations fhe free ends of the impaling prongs are held against all relative motion except an endwise movement apart.

2. In a loose leaf binder: two impaling prongs;

means for mounting the impaling prongs at one end in such a manner that their free ends are endwise engageable to form a closed loop; an interlocking connection between the free ends of the impaling prongs comprising, complementary notches and projections on the free ends of the prongs, the notches of one impaling prong being formed at opposite sides of the median plane of the loop and the notches of the other impaling prong being on the median plane and at right angles to the notches of the first designated impaling prong so that the projections on one align with the notches of the other impaling prong, and the notches of one impaling prong being substantially the same size as the projections on the other so that the projections on one impaling prong fit snugly into the notches of the other.

3. In a loose leaf binder: two impaling prongs; means for mounting the impaling prongs atone end in such a manner that their free ends are 'endwiseengageable to form a closed loop; an interlocking connection between the free ends of the impaling prongs comprising, a pair of substantially V-shaped notches at opposite sides of the free end portion of each impaling prong with the bottom edges of the notches forming acute angles with the axes of the impaling prongs and meeting at saidaxes sothat the free end of each impaling prong is bifurcate with the inner walls of its forks formed by angularly disposed substantially plane surfaces, and the notches in one impalingprong being aligned with the forks on the other impaling prong.

4. In a loose leaf binder: two impaling prongs;

'means for mounting. the impaling prongsat one end in such a manner that'their free endsare endwise engageable to "form a closed loop; an interlocking connection between the free ends of the impaling prongs comprising, a pair of substantially V-shaped notches at opposite sides of the free end portion of each impaling prong with the bottom edges of thenotchesfforming acute angles with the-axes of the impaling prongs and meeting at said axesso'that the free end ofeach impalingvprong is bifurcate with the inner walls of the bifurcation formed by four substantially triangular receding plane surfaces. o

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